Panel colouring of selected/highlighted items - can it be changed?

[Chris Green]

I find the shaded/graded background colour of selected and/or
highlighted app tabs in the panel makes the text difficult to read. Can
one change this to a plain colour?  If so where does one change it?

This seems to apply only to the tabs for opened applications, other
things in the panel seem to have a plain colour when highlighted. If I
could make the active application tabs work the same as other items in
the panel I would be happy.

-- 
Chris Green